How are you guys that braze flowing N2? Almost all the minis i've installed only have 1 access port for each head....

Anyway I always flare ad use the cps tool that has the deeper v on the block to get a nice flare with maximum surface area. Oil on the flare nuts and the flare goes a REAL long way toward leaks. I Vacuum to 100 microns or so and hold it under 500 for 30-60 minutes.

I do mostly Fujitsu and Lennox (Gree) Brand, sometimes Mitsu.